The present invention relates to vehicle brake systems. Generally, brake systems require a dedicated booster device to provide brake force amplification so that the brake force exceeds the input force from a driver's foot on a brake pedal under normal operation. In conventional vehicles with internal combustion engines, the booster device is most typically a vacuum booster. However, in alternative vehicles (e.g., electric vehicles) vacuum from an internal combustion engine may not be available. Thus, brake boost must be provided by other means, such as an electro-mechanical device or a high pressure accumulator. For example, in a full-power brake system (also referred to as a “decoupled” or “brake-by-wire” system) in which driver applied force is not used whatsoever to produce the actual braking force to the brake devices, a high pressure accumulator is provided to store a quantity of hydraulic fluid pumped to a high pressure for on-demand application to the brakes. Although satisfactory for the intended purpose, the accumulator adds complexity to the system and inherent component and assembly cost. Furthermore, many vehicles with internal combustion engines have recently adopted direct injection technology, in which vacuum levels may not be sufficient for a conventional vacuum brake booster. This can necessitate the addition of a vacuum pump to generate sufficient vacuum for a brake booster.